Procedural Candlelight
Final:



Node overview:

This is method is quite simple, it's basically make gradient as mask add facing mix and repeat. You can use this approach to extend this material even further and add some more colours, rims, and maybe more.

So here it is:



Mesh:

Flame is modeled from Cylinder, but you can make it as you like. Even from beveled Bezier Curve (easy animation).



Compositing:

As a final touch you can add some Compositing. I've done very simple colour correction, added Glow and Lens Distortion.



Everything should be pretty clear, but if you have any question don't hesitate to ask in comments.